Many transparent, translucent, or other non-opaque materials are produced in long webs or sheets. One characteristic of these types of materials is haze, which refers generally to the scattering of light passing through the materials. Haze typically reduces the contrast of objects viewed through the materials. For example, haze in a plastic sheet used in product packaging might reduce the clarity of lettering viewed through the plastic sheet. Low haze may be important or essential for certain applications, such as consumer electronics packaging or medical device packaging.
Haze measurements typically occur in laboratory settings. For example, a sample of a material can be positioned against an entrance port of an integrating sphere, which can measure the haze of the sample. However, conventional laboratory instruments for measuring haze are typically not suitable for use in a manufacturing or processing environment. Moreover, conventional laboratory instruments for measuring haze are typically contact-type devices, meaning the devices must be placed in physical contact with a material.